An axial air gap motor in which a stator and a rotor are aligned in a rotation axis direction is known. Among such motors, a motor is known in which the rotor and the stator are arranged such that they are relatively movable with each other, and a cam mechanism which changes the distance between the rotor and the stator using the torque of the rotor is provided (refer to Patent Document 1). In addition, there are Patent Documents 2 and 3 as prior art references in relation to the present invention.